MCQs in Computer Science - Timothy Williams

Question

Memory Protection is of no use in

a) single user systems

b) non multiprogrammed systems

c) non multitasking systems

d) none of the above

Comments

B) NON MULTI PGMED SYSTEM

Answer 1

multiprogramming as a way to allow multiple programs being resident in main memory and (apparently) running at the same time.

Then, multitasking refers to multiple tasks running (apparently) simultaneously by sharing the CPU time.

Finally, multiprocessing describes systems having multiple CPU

No multiprogramming no memory protection needed...

Comments

Difference between multiprogramming and multitasking explain in detail plz @gabbar

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Here is my shot :

Muliprogramming : Several jobs are kept in main memory that are ready to be executed. When this job in execution needs an input/output, Instead of waiting for the job to complete input/output, we switch to some other jobs waiting for the cpu ( so that CPU is not idle )

Multitasking : It is a logical extension to multiprogramming where multiple jobs are executed by the CPU switching among them ( means CPU is shared amomg processes on the basis of time). Also called as Time Sharing.

So, in multiprogramming our main aim is that cpu should not be idle for some time ( there must always be a job for cpu to execute), whereas in multitasking processes share the cpu based on time ( suppose after every $t$ sec. every other process will get a chance)

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Sir, what about the OS that resides on memory? Even if one process runs on a single processor, memory protection should be used so that the process does not accidentally overwrite OS pages, no?